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ČERNÝ, M. ŠESTÁK, P. POKLUDA, J. ŠOB, M.
Original Title
Shear instabilities in perfect bcc crystals during simulated tensile tests
Type
journal article in Web of Science
Language
English
Original Abstract
This work demonstrates a simple but efficient way how to determine the existence of shear instabilities in ideal bcc crystals under uniaxial loading. The theoretical tensile strengths are derived from calculated values of the theoretical shear strength and their dependence on the superimposed normal stress. The presented procedure enables us to avoid complicated and time-consuming analyses of elastic stability of crystals. Results of first-principles simulations of coupled shear and tensile deformations for two most frequent slip systems ({110}<111> and {112}<111>) in six ideal cubic crystals are used to evaluate the uniaxial tensile strengths in three low-index crystallographic directions (<100>, <110>, and <111>) by assuming a shear instability in the weakest shear system. While instabilities occurring under <100> tension are mostly related to the shear in {112} plane, those occurring during loading in the other two directions are associated with {110} planes. The results are consistent with those predicted by available elastic analyses. The weakest tendency to fail by shear is predicted for uniaxial tension along <100>. This is consistent with occurrence of {100} cleavage planes in bcc metals.
Keywords
theoretical strength, uniaxial loading, shear instabilities, bcc crystals, ab initio calculations
Authors
ČERNÝ, M.; ŠESTÁK, P.; POKLUDA, J.; ŠOB, M.
RIV year
2013
Released
29. 1. 2013
ISBN
1098-0121
Periodical
PHYSICAL REVIEW B
Year of study
87
Number
1
State
United States of America
Pages from
014117
Pages to
Pages count
4
BibTex
@article{BUT97138, author="Miroslav {Černý} and Petr {Šesták} and Jaroslav {Pokluda} and Mojmír {Šob}", title="Shear instabilities in perfect bcc crystals during simulated tensile tests", journal="PHYSICAL REVIEW B", year="2013", volume="87", number="1", pages="014117--014117", doi="10.1103/PhysRevB.87.014117", issn="1098-0121" }